Cotton batting



May 31, 1938. R a DWI H 2,119,129

COTTON BATTING Filed May 21, 1937 BLEAcnEn WM 14 MM ATTORNEYS,

BY- 2 o9 HYVENTOR.

Patented May 31, 1938 UNITED STATES PATENT OFFHQE COTTON BATTING Application May 21, 1937, Serial No. 144,014

6 Claims.

This invention is directed to cotton membranes or wadding, which are adapted to use for packing, padding, or surgical dressing purposes, and to a method of making them. The application is a continuation-in-part of my patent application Serial No. 100,902, filed September 15, 1936, now issued into Patent No. 2,034,796, dated June 22, 1937.

In my copending application I have described cotton batting comprised of layers or laminations of cotton fibres which alterntely are of the bleached and of the unbleached variety. The discovery upon which that invention is based resides in the determination that the association of layers of cotton, dominantly of the unbleached type, with layers of cotton, dominantly of the bleached type, provides cotton batting possessing all, or substantially all, of the flufilness or sleaziness of raw cotton, (which is quite dark and dirty in color appearance), and all, or substantially all, of the whiteness or clarity of color of the bleached cotton (which is substantially dead or lifeless). Such cotton batting peculiarly is warmer and has better heat insulating properties than cotton batting of the conventional variety comprised entirely of raw or bleached cotton.

The present invention is predicated upon the discovery that a single layer of bleached cotton combined with a single layer of raw cotton possesses properties which make it extremely useful for wet dressing purposes. The most notable of these is the property which the material exhibits of retaining or absorbing large quantitiesof water without exuding it. In other words, the discovery is that a relatively thin layer of raw cotton, associated with a relatively thick layer of bleached cotton, provides a composition which possesses the capacity to absorb as much as 500 to 1000 times its own weight of water, but the raw cotton prevents the absorbed water in the bleached cotton layer from exuding or escaping its retention in the bleached cotton layer.

Briefly, the cotton membranes of the present invention are comprised of a relatively thick layer of bleached cotton. If it is intended to use these cotton membranes for surgical purposes, then this bleached cotton layer is rendered antiseptic in the conventional manner. The ordinary bleaching operation generally is quite suflicient to provide sterilization.

Next, a relatively thin layer of raw cotton is associated with this thick layer of bleached cotton fibres. The two layers are associated in the conventional manner so that intertwining of the fibres of the two types takes place so as to integrate the layers.

In the drawing, Figure 1 illustrates the relationship of the raw cotton fibre layer 2, with the bleached cotton fibre layer 3.

While the combination of cotton fibres according to the invention is a relatively simple one, the remarkable and unexpected feature is that the layer of raw cotton, in a very practical way, prevents escape of water or other liquid saturating the fibres of the adjacent layer. For example, if a thimblefull of water is poured onto a small pad of wadding about one-eighth inch in thickness and weighing approximately .08 ounce per square foot, comprised entirely of absorbent cot- 615 ton, the water seeps through the pad, and appears at the other side in approximately fifteen to twenty seconds. If a thimblefull of water is poured onto a pad of substantially the same size and same thickness, but made in accordance with 120 the present invention and comprised of approximately absorbent cotton in association with a layer of non-absorbent or raw cotton batting, then the water will penetrate through the absorbent cotton down to the point that it reaches 2 the raw cotton layer, after which no further penetration will take place, even though enough water thereafter is poured onto the pad thoroughly to saturate it. Moreover, a saturated pad of this type will retain substantially all of the moisture, or water, without permitting any to drip through when the pad is allowed to stand overnight in its saturated form. Of course, severe creasing of the pad tends to permit the passage of water therethrough because it causes compaction of the fibres at a local area through which water can escape.

The articles of the invention are adapted particularly to use as wet dressings for surgical purposes, or as wet packings, for instance, by nurserymen and packers, and in other instances where it is desired to maintain material in a definitely moist state. If the compositions of the invention are to be used as wet surgical dressings, then the medicinal or pharmaceutical liquids are applied to the bleached or absorbent layer, and this layer then is placed in contact with the skin, or at the area desired to be treated. The outer layer of fibres of raw cotton is sufiiciently resistant to the passage of liquid therethrough to prevent escape of the liquid from the dressing in its ordinary course of usage. Of course, it is possible to squeeze liquid from the dressing if it is saturated completely. However, the dressings will remain actually wet for a period anywhere from five to fifty times longer than the wet dressings prepared from the conventional absorbent cotton, when they are exposed to the ordinary dry atmosphere. Of course, these figures are only approximate, since it is relatively impossible to determine moisture retention values with any degree of accuracy by reason of the fact that the factor of evaporation of moisture from the surfaces of the pads has to be considered, and evaporation is dependent largely upon surface exposure conditions.

If it is desired, one or both surfaces of the membrane of cotton of the present invention may be glazed, or sized in the conventional manner, with a starch, dextrin, or other suitable sizing. Sizing of the membrane is particularly advantageous when the membrane is to be used for packing purposes, other than in surgery, Where the presence of sizing or other foreign materials is undesirable. Cheesecloth or a textile fabric may be used with, or applied to the membrane, or paper may be applied to the non-absorbent layer if it is desirable to provide a membrane having increased strength.

In the practice of the present invention, it is preferred to constitute the absorbent layer from bleached cotton fibres in a conventional cotton batting machine, until a layer of approximately 0.4 to 1 ounce per square foot in weight is obtained. The thickness, of course, depends upon the usage which is intended for the membrane. Ordinarily, only a relatively thin skin is required to constitute the raw cotton fibre layer. This layer may be anywhere from 0.1 to 0.2 ounce per square foot in Weight, or more, depending upon the intended usage, though a layer which is approximately 0.2 ounce per square foot in thickness is preferred. The raw cotton fibre layer may be made thicker if a particularly moisture resistant membrane is desired. When the bleached cotton fibre layer and the raw cotton layer are associated, the fibres intertwine and a relatively integral membrane, which is quite strong, is provided. This membrane is cut into lengths and rolled for packaging. If the packages contain membranes intended to be used for surgical purposes it is recommended that the cotton be given a final sterilizing treatment after it has been packaged.

Having described my invention, I claim:

1. A cotton batting composition, which possesses the capacity toabsorb a large amount of liquid and to hold this liquid when the batting is used as a wet dressing, which cotton batting composition comprises a relatively thick layer of absorbent cotton fibres and a relatively thin layer of cotton fibres of the type exemplified by raw cotton fibres.

2. A cotton membrane adapted to use for surgical purposes, comprising a relatively thick layer of fibres of absorbent cotton and a relatively thin layer of fibres of raw cotton associated therewith.

3. A cotton batting composition adapted for Wet dressing purposes, which comprises a layer of fibres of cotton which possess the capacity to absorb a large quantity of liquid, and a layer of fibres of raw cotton.

4. A surgical cotton membrane, which comprises a relatively thick layer of absorbent cotton fibres and a relatively thin layer of raw cotton fibres, the thick layer of absorbent fibres adapted to absorb a large quantity of liquid and the thin layer of raw cotton fibres adapted to prevent migration of the liquid absorbed in the thick layer from the cotton membrane When it is used as a dressing.

5. A cotton membrane adapted to use for surthe thick layer of absorbent fibres adapted to I, absorb a large quantity of liquid and the thin layer ,of raw cotton fibres adapted to prevent migration of the liquid absorbed in the thick layer from the cotton membrane when it is used as a dressing, and a textile fabric associated with the membrane to give it strength.

RUSSELL S. DWIGHT. 

